An important factor in cellular growth and metabolism is the biosynthesis degradation, and transport of amino acids. This project emphasizes the regulatory interplay in amino acid metabolism. BIBLIOGRAPHIC REFERENCES: Valle, D., Goodman, S.I., Appelgarth, D.A., Shih, V.E. and Phang, J.M.: Type II hyperprolinemia: delta 1-pyrroline-5-carboxylic acid dehydrogenase deficiency in cultured skin fibroblasts and circulating lymphocytes. J. Clin. Invest. 58:598-603, 1976. Kowaloff, E.M., Granger, A.S. and Phang, J.M.: Alterations in proline metabolic enzymes with mammalian development. Metabolism 25:1087-1094, 1976.